Storage devices may be employed in various secure applications to store protected data. For example, a semiconductor memory circuit may be used in a smartcard, set-top box, Subscriber Identity Module (SIM) card or banking card to store user identification information, account information, device preference information or electronic payment authorization information.
Because of the potential value of protected data stored in a storage device, hackers may employ various techniques to access or corrupt the protected data. For example, a hacker may grind off a portion of the storage device packaging in order to access internal signals and bypass security measures that may be in place. As another example, a hacker may subject the storage device to various kinds of radiation (e.g., laser light directed to exposed internal circuits or x-ray or gamma radiation directed through packaging) in an attempt to corrupt protected data. In some devices, corruption of protected data at certain locations in the device may cause the device to bypass security measures (e.g., encryption algorithms) or to yield information to the hacker regarding device architecture or the protected data itself.